One of the key drugs that the British armed forces gave to soldiers serving in the Gulf War is so old that it precedes the date at which rigorous tests were introduced before a drug could be commercialised.
The news highlights the importance of a pilot study, published by Glasgow-based neurologist Goran Jamal, which says that Gulf War veterans with so-called Gulf War syndrome may have damaged nervous systems due to exposure to nerve agent pre-treatment sets (Naps).
Pyridostigmine bromide, a key component of Naps, was given to soldiers as an antidote to potential chemical and biological attacks. It protects neurotransmitters carrying messages to the brain.
The drug was first produced in 1955, well before the 1968 medical act which introduced stringent studies of drugs before approval.
Robert Smith, a specialist in adverse reactions to drugs at Imperial College, London, said: "A lot of drugs introduced in the 1950s are used as a right." It was only after the thalidomide disaster that new controls were introduced, he said, and there had been an attempt to catch up by testing old drugs, but it had not been comprehensive.
PB was originally intended for the treatment of severe muscle weakness, known as myasthenia gravis. But medical textbooks warn that "large doses given initially may precipitate a myasthenic crisis" - ie, can make the patients worse than they were. Side effects include nausea, heart abnormalities, agitation and involuntary muscle movements.
Dr Jamal, who led the study of 14 veterans and 13 healthy civilians, said that he discovered damage to the peripheral nerve function in the veterans.
The Ministry of Defence has been criticised by researchers and by the House of Commons defence select committee for its slow response to calls for research into the syndrome. Last January, five years after the war began, it announced that it would fund studies into deformities suffered by children of Gulf War veterans. One study, believed to cost about Pounds 500,000 a year for three years, will be overseen by the Medical Research Council, whose Physiological Medicines and Infections Board will have advertised and selected a shortlist of detailed proposals by October.
The other study will look at the possible effects on the unborn of certain chemicals, toxins and stress.